Mach

Mach
Logging into a Mach/Lites/NetBSD system
Type:	Multitasking, multiuser
Creator:	CMU
Architecture:	m68k, i386, POWER, HPPA, Sparc
This Version:	3.0 (1994)
Date Released:	1985

Mach was the microkernel from CMU that popularized the microkernel craze of the late 1980's and into the 1990's. While seen as a dead end effort, it did at the time bring in many new things to the aging Unix kernel. Mach, based loosely on BSD was a low level kernel adding threads insteads of forked processes, and had the ability to run on SMP hardware. BSD was then ported back as a user process ontop of the Mach micro kernel.

Some of the operating systems that used Mach were NeXTSTEP/OPENSTEP & OSF/1. The GNU Hurd project also used Mach at one point before abandoning it for L4. There was even some 'free' verions of Mach that started to ship after the opening up of the BSD source code.

After 1994 Mach 3.0 was picked up by the University of Utah, who released Mach 4.0, and the OSKit. Then they focused on L4.

The GNU project had taken a version of Mach, and used the GNU license to 'gnu-ify' mach and produce GNUMach. While Windows NT may share design ideas with Mach, it is NOT a derived Mach microkernel.